Preheat oven to 400°. In a large bowl, combine flour, sugar and lemon zest. Cut in butter until crumbly. Whisk egg yolks and vanilla; add to flour mixture, tossing with a fork until dough forms a ball. , Press onto bottom and 3 in. up sides of a greased 9-in. springform pan. Place pan on a baking sheet. Bake until golden brown, 12-15 minutes. Cool on a wire rack., For filling, in a large bowl, beat cream cheese and sugar until smooth. Beat in cream, flour, lemon zest, salt and vanilla. Add eggs and yolk; beat on low speed just until combined., Divide batter in half. Fold crushed strawberries and crushed blueberries into half of the batter. Pour into crust. Top with remaining batter. Return pan to baking sheet., Bake at 400° for 10 minutes. Reduce heat to 300° bake 60-70 minutes longer or until center is almost set. Cool on a wire rack 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour. Refrigerate overnight. Remove sides of pan., Garnish with fresh mixed berries and currants, if desired.